There are technologies available that provide federation across publish/subscribe message brokers. Typically they extend the hub and spoke model used for communicating via a message broker to provide other models for communication such as a bus or mesh. A network of connections is established between brokers along which publish/subscribe information and messages are sent. The result is an extension of publish/subscribe messaging that allows the client to subscribe to sources from a remote broker to which they do not have a direct connection. An example implementation of federated publish/subscribe message brokers is the Fabric for Sensor Network Management and Data Transfer (The Fabric) of International Business Machines Corporation.
Data efficiency is important for these types of federation technologies. As such the amount of data (in terms of both the number of packets and the number of bytes) sent is a high focus area in order to make them as efficient as possible. One of the primary goals of the original design of The Fabric is usage on small devices at the edge of the network. In this scenario data efficiency is a primary concern as the networks available for interconnection of devices can be very slow, expensive and unreliable e.g. radio networks. The available bandwidth must be utilised as efficiently as possible.
The federation technology linking brokers together will typically only send one message between two brokers even if there are many subscribers to the topic on which the message is being sent. This is an efficiency saving for network usage that means multiple copies of the same message are not sent between brokers when many subscribers are present.
Current technologies are intelligent enough to inspect the data and take account of in-flight message processing such that additional copies of the message are only sent on to other brokers in the scenario where the message has been processed and an update to the message has resulted. In this scenario the original message and a new copy of that message including the updated information would be passed between federated brokers (assuming clients are subscribed to both messages).
Therefore, there is a need in the art to address the aforementioned problems.